Vibration generating device

Abstract

To provide a vibration generator capable of improving portability.SOLUTION: The vibration generation device includes a piezoelectric first actuator that applies a first vibration to an object, an electromagnetic second actuator that applies a second vibration to the object, and a support member that supports the first actuator and the second actuator, and the first actuator and the second actuator are attachable to and detachable from the object.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates to a vibration generating device. [Background technology]

[0002] 2. Description of the Related Art There are known vibration generating devices such as speakers that vibrate a diaphragm using a piezoelectric element and vibrate another diaphragm using a coil and a magnet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6578554 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-238285 [Patent Document 3] Patent No. 3809917 [Patent Document 4] Japanese Patent Application Laid-Open No. 2006-319626 [Patent Document 5] Patent No. 6195869 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been an increasing demand for improved portability of vibration generators so that music and the like can be reproduced in various places.

[0005] An object of the present disclosure is to provide a vibration generating device that can improve portability. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, a vibration generating device includes a first piezoelectric actuator that imparts a first vibration to an object, a second electromagnetic actuator that imparts a second vibration to the object, and a support member that supports the first actuator and the second actuator, and the first actuator and the second actuator are detachable from the object. [Effects of the Invention]

[0007] According to the present disclosure, portability can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a vibration generator according to a first embodiment. [Figure 2] FIG. 2 is a bottom view showing the vibration generator according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing a first actuator. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 2 is a cross-sectional view showing a piezoelectric element. [Figure 7] FIG. 4 is a perspective view showing a second actuator. [Figure 8] FIG. 10 is a top view showing a vibration generator according to a second embodiment. [Figure 9] FIG. 10 is a bottom view showing a vibration generator according to a second embodiment. [Figure 10] FIG. 10 is a side view showing a vibration generator according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes in detail embodiments of the present disclosure, but the present disclosure is not limited thereto. In this specification and drawings, components having substantially the same functional configuration may be designated by the same reference numerals to avoid redundant description. In the following description, an XYZ Cartesian coordinate system is used, but this coordinate system is defined for the purpose of explanation and does not limit the orientation of the vibration generator. Furthermore, when viewed from an arbitrary point, the +Z side may be referred to as the upper side, upper side, or top, and the -Z side may be referred to as the lower side, lower side, or bottom.

[0010] (First embodiment) A first embodiment will be described. The first embodiment relates to a vibration exciter. FIG. 1 is a cross-sectional view showing the vibration exciter according to the first embodiment. FIG. 2 is a bottom view showing the vibration exciter according to the first embodiment. FIG. 1 corresponds to a cross-sectional view taken along line II in FIG. 2.

[0011] As shown in Figures 1 and 2, the vibration generator 1 according to the first embodiment has a piezoelectric first actuator 100, an electromagnetic second actuator 200, and a support member 300 that supports the first actuator 100 and the second actuator 200.

[0012] Fig. 3 is a cross-sectional view showing the first actuator. As shown in Fig. 3, the first actuator 100 has piezoelectric elements 11 and 12, intermediate members 21 and 22, and a housing 90. The housing 90 has a cylindrical body 50 and fastening members 110 and 120.

[0013] Fig. 4 is a cross-sectional view showing the cylindrical body 50. As shown in Fig. 4, the cylindrical body 50 has a through-hole 60 extending along the Z-axis. The through-hole 60 has a central portion 61 and end portions 62 and 63. The end portion 62 is provided on the +Z side of the central portion 61, and the end portion 63 is provided on the -Z side of the central portion 61.

[0014] The cross section of the center 61 perpendicular to the Z axis has a substantially rectangular shape, and the cross sections of the end portions 62 and 63 perpendicular to the Z axis have a substantially circular shape. A thread 64 that becomes a female screw is formed on the inner surface of the end portion 62, and a thread 65 that becomes a female screw is formed on the inner surface of the end portion 63. No thread is formed on the inner surface of the center 61.

[0015] Piezoelectric elements 11 and 12 are provided in a central portion 61. Piezoelectric element 11 is provided on the +Z side of piezoelectric element 12. Intermediate member 21 is provided in an end portion 62 on the +Z side of piezoelectric element 11. Intermediate member 22 is provided in an end portion 63 on the -Z side of piezoelectric element 12.

[0016] In this way, the intermediate member 21, the piezoelectric element 11, the piezoelectric element 12, and the intermediate member 22 are lined up along the Z axis in this order inside the through hole 60. For example, the intermediate member 21, the piezoelectric element 11, the piezoelectric element 12, and the intermediate member 22 are separated from the inner surface of the through hole 60 and are not in contact with the inner surface. The Z axis is an example of the first axis.

[0017] FIG. 5 is a cross-sectional view showing a fastening member. FIG. 5(a) shows a fastening member 110, and FIG. 5(b) shows a fastening member 120. As shown in FIG. 5(a), the fastening member 110 has a head 111 and a threaded portion 112. The cross-section of the head 111 perpendicular to the Z axis is substantially circular. A thread 113 that becomes a male screw is formed on the outer surface of the threaded portion 112. The thread 113 fits into the thread 64 of the end portion 62. As shown in FIG. 5(b), the fastening member 120 has a head 121 and a threaded portion 122. The cross-section of the head 121 perpendicular to the Z axis is substantially circular. A thread 123 that becomes a male screw is formed on the outer surface of the threaded portion 122. The thread 123 fits into the thread 65 of the end portion 63. By tightening the screws, the fastening member 110 presses the intermediate member 21 to the -Z side, and the fastening member 120 presses the intermediate member 22 to the +Z side. As a result, a compressive stress acts on the piezoelectric elements 11 and 12 along the Z axis.

[0018] The material of the cylindrical body 50 and the fastening members 110 and 120 is, for example, metal or resin. The Young's modulus of each of the intermediate members 21 and 22 is greater than the Young's modulus of each of the piezoelectric elements 11 and 12, the cylindrical body 50, and the fastening members 110 and 120. The material of the intermediate members 21 and 22 is, for example, stainless steel, aluminum, or an aluminum alloy.

[0019] Next, the piezoelectric elements 11 and 12 will be described. Fig. 6 is a cross-sectional view showing the piezoelectric elements. Fig. 6 shows the piezoelectric element 11. The piezoelectric element 12 has the same configuration as the piezoelectric element 11.

[0020] As shown in FIG. 6 , the piezoelectric element 11 includes a piezoelectric body 30 made of multiple first piezoelectric layers 31, multiple first electrodes 32, and multiple second electrodes 34. The multiple first piezoelectric layers 31 are stacked in the Z-axis direction. The first piezoelectric layers 31, the first electrodes 32, and the second electrodes 34 are flat plates extending in the XY plane. The multiple first electrodes 32 and the multiple second electrodes 34 are arranged alternately in the Z-axis direction. One first piezoelectric layer 31 is sandwiched between one first electrode 32 and one second electrode 34 in the Z-axis direction. A first external electrode 33 is provided on the side surface of the piezoelectric body 30 on the −X side, and a second external electrode 35 is provided on the side surface of the piezoelectric body 30 on the +X side. The multiple first electrodes 32 are electrically connected to the first external electrode 33. The multiple second electrodes 34 are electrically connected to the second external electrode 35. By applying a voltage between the first external electrode 33 and the second external electrode 35, the piezoelectric body 30 expands and contracts in the Z-axis direction due to the inverse piezoelectric effect. A vibration mode in which the first electrode 32 and the second electrode 34 expand and contract in the stacking direction of the first electrode 32 and the second electrode 34 by applying a voltage to the first electrode 32 and the second electrode 34 is called a longitudinal displacement mode or d33 mode.

[0021] The piezoelectric body 30 includes a first region 36, a second region 37, and a third region 38. The first region 36 and the second region 37 are alternately arranged in the Z-axis direction. The third region 38 is arranged outside the first region 36, which is the outermost in the Z-axis direction. The first region 36 is a region in which the first electrodes 32 and the second electrodes 34 are alternately arranged at regular intervals in the Z-axis direction. The number of stacked layers of the first piezoelectric layer 31 in the first region 36 is, for example, 50. The second region 37 and the third region 38 are regions in which the first electrodes 32 and the second electrodes 34 are not provided. The second region 37 does not have to be provided. Providing the second region 37 may improve reliability in some cases.

[0022] Examples of materials that can be used for the first piezoelectric layer 31 include lead zirconate titanate (PZT: Pb(Zr,Ti)O3), barium titanate-based materials (BaTiO3, where Ba may be Ca and Ti may be Zr), bismuth titanate-based materials (BiTiO3, where part of Bi may be Na), and alkali niobate-based materials (NaNbO3, where Na may be Li or K). Examples of materials that can be used for the first electrode 32, the second electrode 34, the first external electrode 33, and the second external electrode 35 include metals such as Ag, Pd, Pt, Cu, Ni, and Au.

[0023] The piezoelectric element 11 is a chip made of a sintered body formed by stacking and sintering piezoelectric sheets each having a first electrode 32 and a second electrode 34 formed on its surface. The shape of the piezoelectric element 11 is, for example, a rectangular parallelepiped, and the widths of the piezoelectric element 11 in the X-axis and Y-axis directions are, for example, 3.5 mm, and the height in the Z-axis direction is 3 mm.

[0024] When the displacement ΔZ in the Z-axis direction on the ±Z side surfaces of the piezoelectric element 11 is N, the number of layers of the first piezoelectric layer 31 is V, the voltage applied between the first electrode 32 and the second electrode 34 is V, and the constant related to the inverse piezoelectric constant is d33, then ΔZ = d33 × V × N. Therefore, increasing the number N of layers of the first piezoelectric layer 31 increases the displacement ΔZ.

[0025] When the cylindrical body 50, the fastening members 110, and the fastening members 120 press the piezoelectric elements 11 and 12 along the Z axis, the Q value is improved compared to when the piezoelectric elements 11 and 12 are not pressed. This phenomenon is not obtained when piezoelectric elements of a lateral displacement mode are used as the piezoelectric elements 11 and 12, and was discovered for the first time by the present inventors. The lateral displacement mode is a mode in which the vibration direction of the piezoelectric elements 11 and 12 is perpendicular to the stacking direction of the first electrode 32 and the second electrode 34. The resonant frequency does not change much depending on whether the piezoelectric elements 11 and 12 are pressed or not. This is thought to be due to the presence of the intermediate members 21 and 22.

[0026] In this way, the piezoelectric elements 11 and 12 can expand and contract along the Z axis, and the piezoelectric elements 11 and 12 can be pressed along the Z axis by the cylindrical body 50 and the fastening members 110 and 120. This improves the Q value of the mechanical vibration of the housing 90. For example, by controlling the expansion and contraction of the piezoelectric elements 11 and 12, it is possible to generate high-output vibrations. More specifically, the fastening member 120 vibrates as a first oscillator that imparts a first vibration to the object 10. The fastening member 120 has a first surface 125 that faces the object 10. The first actuator 100 is detachable from the object 10.

[0027] FIG. 7 is a perspective view showing the second actuator. As shown in FIG. 7, the second actuator 200 has a driving unit 210 and a vibrator 220. The driving unit 210 and the vibrator 220 have a substantially circular shape in a plan view perpendicular to the XY plane. The driving unit 210 has a magnet and a coil, and vibrates the vibrator 220. The vibrator 220 vibrates as a second vibrator that imparts a second vibration to the object 10. The vibrator 220 has a second surface 225 that faces the object 10. The second actuator 200 is detachable from the object 10.

[0028] As shown in FIG. 1, the support member 300 has an upper surface 301 and a lower surface 302 parallel to the XY plane. A through-hole 311 extending parallel to the Z axis is formed in the support member 300, and the first actuator 100 is attached to the through-hole 311. In FIG. 1, the structure of the first actuator 100 is simplified. The head 111 of the clamping member 110 is located on the +Z side of the upper surface 301, and the head 121 of the clamping member 120 is located on the -Z side of the lower surface 302. A recess 312 is formed in the lower surface 302, and the second actuator 200 is attached to the recess 312. A drive unit 210 is fixed to the bottom surface of the recess 312. The first surface 125 of the clamping member 120 serving as the first vibrator and the second surface 225 of the vibrator 220 serving as the second vibrator are preferably parallel to each other, and more preferably flush with each other. The support member 300 is made of a material such as polyacetal resin.

[0029] As shown in FIG. 1 , the vibration generator 1 is detachably fixed to the object 10 so that the first surface 125 and the second surface 225 are in contact with the object 10. The object 10 is, for example, a plate material. The object 10 may have a honeycomb structure. The material of the object 10 is, for example, glass, acrylic resin, wood, metal, plaster, etc. Examples of metals that can be used include brass and stainless steel. When the first piezoelectric actuator 100 applies a first vibration to the object 10, the object 10 vibrates the air, emitting a particularly strong high-frequency sound, for example, of about 1 kHz to 20 kHz. When the second electromagnetic actuator 200 applies a second vibration to the object 10, the object 10 vibrates the air, emitting a particularly strong low- to mid-frequency sound, for example, of about 10 Hz to 8 kHz.

[0030] Therefore, the vibration generator 1 can generate strong sounds over a wide frequency band of approximately 10 Hz to 20 kHz through the object 10. Furthermore, the first actuator 100 and the second actuator 200 are detachable from the object 10 that directly vibrates the air, and the vibration generator 1 does not need to be equipped with the object 10. Therefore, the vibration generator 1 can generate strong sounds over a wide frequency band and can also be made more portable.

[0031] It is not necessary for the first surface 125 and the second surface 225 to be in direct contact with the object 10. For example, an adhesive sheet or the like that has good vibration transmission properties may be provided between the first surface 125, the second surface 225 and the object 10.

[0032] (Second embodiment) A second embodiment will now be described. The second embodiment relates to a vibration exciter. Fig. 8 is a top view of the vibration exciter according to the second embodiment. Fig. 9 is a bottom view of the vibration exciter according to the second embodiment. Fig. 10 is a side view of the vibration exciter according to the second embodiment.

[0033] As shown in Figures 8 to 10, the vibration generator 2 according to the second embodiment has two piezoelectric first actuators 100, an electromagnetic second actuator 200, and a support member 300 that supports the first actuators 100 and the second actuators 200.

[0034] In the vibration generator 2, the support member 300 has a rounded equilateral triangular shape in a plan view perpendicular to the XY plane. Through holes 311 are formed near two vertices of the support member 300, and a first actuator 100 is attached to each of the through holes 311. A recess 312 is formed in the bottom surface 302, and a second actuator 200 is attached in the recess 312. In the vibration generator 2, a recess 313 is formed in the top surface 301. The recess 313 is connected to the recess 312. In a plan view perpendicular to the XY plane, the recess 313 is located inside the recess 312. The drive unit 210 is exposed from the recess 313.

[0035] A leg member 320 is provided on the lower surface 302 near the remaining vertex of the support member 300. The leg member 320 has a third surface 325 that faces the object 10. The leg member 320 is attachable to and detachable from the object 10.

[0036] It is preferable that the first surface 125 of the fastening member 120 as the first vibrator of the two first actuators 100, the second surface 225 of the vibrator 220 as the second vibrator, and the third surface 325 of the leg member 320 are parallel to each other, and it is more preferable that they are flush with each other.

[0037] Other configurations of the electromagnetic exciter 2 are the same as those of the electromagnetic exciter 1.

[0038] The vibration generator 2 can also generate strong sounds over a wide frequency range and improve portability. Furthermore, the posture of the vibration generator 2 is determined by the two fastening members 120 and the leg members 320. Therefore, it is easier to stabilize the posture than the vibration generator 1.

[0039] Since recess 313 communicates with recess 312 and driving unit 210 is exposed from recess 313, an ornament that bounces up due to vibration may be provided inside recess 313. In this case, the user can enjoy the operation of vibration generator 2 not only through hearing but also through sight.

[0040] The circuit may be configured so that one of the two first actuators 100 applies a first vibration to the object 10, and the other functions as a piezoelectric pressure sensor that detects external vibrations by the piezoelectric effect. In this case, the other first actuator 100 can be used as an input switch or a sound sensor.

[0041] Although the embodiments have been described in detail above, the present disclosure is not limited to the specific embodiments, and various modifications and changes are possible within the scope of the claims.

[0042] Aspects of the present disclosure are, for example, as follows.

[0043] <1> a first piezoelectric actuator that applies a first vibration to the object; a second electromagnetic actuator that applies a second vibration to the object; a support member that supports the first actuator and the second actuator; and The vibration generating device, wherein the first actuator and the second actuator are detachable from the object.

[0044] <2> the first actuator has a first vibrator having a first surface facing the object; the second actuator has a second vibrator having a second surface facing the object; <1> The vibration generating device according to claim 1.

[0045] <3> The first surface and the second surface are parallel to each other. <2> The vibration generating device according to claim 1.

[0046] <4> The first surface and the second surface are flush with each other. <2> The vibration generating device according to claim 1.

[0047] <5> the first actuator has one or more piezoelectric elements; The piezoelectric element is a piezoelectric layer; a first electrode and a second electrode sandwiching the piezoelectric layer along a first axis perpendicular to the first surface; and When a voltage is applied between the first electrode and the second electrode, the piezoelectric layer expands and contracts along the first axis. <2> ~ <4> The vibration generating device according to any one of the preceding claims.

[0048] <6> A plurality of the first actuators are supported on the support member. <1> ~ <5> The vibration generating device according to any one of the preceding claims.

[0049] <7> a piezoelectric pressure sensor supported by the support member; <1> ~ <6> The vibration generating device according to any one of the preceding claims. [Explanation of symbols]

[0050] 1, 2: Vibration generator 10:Object 11, 12: Piezoelectric element 90: Cabinet 100: First actuator 110, 120: Fastening members 111, 121: Head 125: 1st page 200: Second actuator 210: Drive unit 220: Vibrator 225: 2nd side 300: Support member 301:Top surface 302: Bottom surface 311: Through hole 312, 313: recess 320: Leg member 325:Side 3

Claims

1. a first piezoelectric actuator that applies a first vibration to an object; a second electromagnetic actuator that applies a second vibration to the object; a support member that supports the first actuator and the second actuator; and The vibration generating device, wherein the first actuator and the second actuator are detachable from the object.

2. the first actuator has a first vibrator having a first surface facing the object; The vibration generator according to claim 1 , wherein the second actuator has a second vibrator having a second surface facing the object.

3. The vibration generator according to claim 2 , wherein the first surface and the second surface are parallel to each other.

4. The vibration generator according to claim 2 , wherein the first surface and the second surface are flush with each other.

5. the first actuator has one or more piezoelectric elements; The piezoelectric element is a piezoelectric layer; a first electrode and a second electrode sandwiching the piezoelectric layer along a first axis perpendicular to the first surface; and The vibration generator according to claim 2 , wherein the piezoelectric layer expands and contracts along the first axis by applying a voltage between the first electrode and the second electrode.

6. The vibration generator according to claim 1 , wherein a plurality of the first actuators are supported by the support member.

7. The vibration generator according to claim 1 , further comprising a piezoelectric pressure sensor supported by the support member.

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